Timer utilizing spring clutch

ABSTRACT

A coil spring is frictionally carried by a member of a drive means which drives a cam programming means of a timer, a distal end of the spring being coupled to a shaft which carries the cam programming means. Electrical contact blade retaining means are formed as integral parts of the timer housing.

United States Patent Brown et al.

154] TIMER UTILIZING SPRING CLUTCH [72] Inventors: William R. Brown, Beech Grove; Veron E. Bang, Indianapolis, both of [73] Assignee: P. R. Mallory & Co. Inc.', Indianapolis, Ind.

[22] Filed: April23, 1971 [21 Appl. No.: 136,773

[52] U.S. Cl ..200/38 B, 64/28 R, 200/38 B [51] Int. Cl. ..H0lh 7/08, HOlh 43/10 [58] Field of Search ..58/37; 64/28 R, 30 R, 30 A; 192/1061, 106.2, 25.1; 200/33 R, 38 R, 38

B, 38 BA, 153 N, 153 P, 153 V [56] References Cited UNITED STATES PATENTS Simmons ..200/38 BA 1 Oct. 24, 1972 Pease ..64/30 R 2,753,406 7/1956 Pigman ..200/38 B 2,963,628 12/1960 Ostland ..200/38 B 3,111,822 11/1963 Hansen ..64/28 R 3,157,258 11/1964 Cronholm ..64/28 R Primary Examiner-J. R. Scott Attorney-Richard 11. Childress, Robert F. Meyer and Henry W. Cummings ABSTRACT A coil spring is frictionally carried by a member of a drive means which drives a cam programming means of a timer, a distal end of the spring being coupled to a shaft which carries the cam programming means. Electrical contact blade retaining means are formed as integral parts of the timer housing.

19 2 Drawing Figures PATENTEDum24 m: 3.700.838

Flam 52 29' INVENTORS 5O VERNON E. BANG WILLIAM RAY BROWN ATTORNEY TIMER UTILIZING SPRING CLUTCH The present invention relates to timing mechanisms and more particularly to a timing mechanism which is neat and compact, and which utilizes a spring clutch means which through its individual compactness and neatness aids in maintaining the overall compactness of the timer.

Timing mechanisms are used in appliances such as washers, dryers, hair dryers, etc. to sequentially operate the appliance in accordance with a programmed sequence. In such mechanisms cam programming means including cams carried by a shaft actuate electrical switches to provide the program sequence. The cam program means are usually driven through a motor drive means which usually includes a speed reduction means such as a gear train. In some instances, the cam programming means can be manually rotated so that a desired starting point of the program cam be manually set. IN such instances, clutching means need to be provided so that the cam programming means can be rotated independent of the motor drive.

In applications such as for hair dryers, the timing mechanism needs to be neat and compact with as little protrusions extending from the body of the timer as possible.

The present invention is concerned with timing mechanisms and has as one of its objects the provision of a timer which is neat and compact.

Another object of the invention is the provision of a timer which utilizes a clutch means so that the cam programming means may be manually rotated independent of the timer motor drive means.

Still another object of the invention is the provision of a clutch means which includes a coil spring frictionally carried by a member of a motor drive means and having a distal end coupled to a rotating shaft driven by the motor drive means.

These and other objects of the invention will become apparent from the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 is an exploded view of a timing mechanism; and

FIG. 2 is an enlarged view showing the cooperating elements of a clutch means used in the timer.

Generally speaking, the objects of the invention are accomplished by providing a timer wherein electrical switch means are responsive to rotation of a cam programming means, the cam programming means responsive to manual drive means and motor drive means, a clutch means permitting the cam programming means to be manually rotated independent of the motor drive means, the clutch means including a spring carried by a member of the motor drive means, and the spring including a distal end engaging the cam programming means.

Referring now to FIG. 1, there is shown a timing device incorporating the novel features of the present invention. The timer is composed of two subassemblies, the motor assembly 11 and the switch timing mechanism 12. The motor assembly includes a synchronous motor 9 and an appropriate gear train 8 which includes gear 7 driving the switch timing mechanism 12 through shaft 13. Gear 7 is independently rotatably carried on shaft 13. The housing or cover for the switch timing mechanism includes a cup shaped member 14 and a cover plate 15 adapted to close the same. Cover plate 15 is securely fastened to a base plate of the housing for the gear train assembly through a plurality of screws 16 which engage internally threaded posts 16' extending through oblong shaped apertures 17. The cup shaped member 14 and the cover plate 15 are preferably fabricated of an electrically insulating material such as a phenolic plastic, for example.

The essential parts of the switch timing mechanism, in general, comprise the switch contact blades 18 and 19 having electrical terminals 18' and 19 integrally formed as part of the blades, cam programming means 29, and contact blade retaining means 32 and 32' formed as an integral part of the cover 15, and cup shaped member 14. Cam programming means 29 includes at least one cam 29' fixedly carried by shaft 13. Shaft 13 is journ'alled in the base of cup shaped member 14 and in cover plate 15. For illustrative purposes, there is shown a step 30 provided in the cam, the step being formed in size and contour according to the desired program. As will be hereinafter described such programming means will, with the proper selection of contact blades 18 and 19, and blade retaining means 32 and 32', allow various switching circuits to be readily obtained, the operation of such circuits being controlled by the timing of the cam programming means 29.

Contact blade 18 is responsive to the cam programming means through the wedge shaped cam follower 33, the follower being formed as an integral part of the blade. Blade 18, being responsive to the cam programming means, is the actuator blade. Movement of the blade 18 causes electrical contact 34 to engage contact 35. Suitable materials for the contact include an electrically conductive material such as copper, for example.

As illustrated in FIG. 1 the timing device of the present invention is adapted to give a single pole, single throw switching circuit arrangement. Cam programming means 29 forces blade 18 to rise when the wedge shaped cam follower 33 rides up and over the discrete arcuate step 30 thus closing contacts 34 and '35. Because of the contact blade retaining means 32 and 32 the blades readily return to their original position when cam follower 33 again reaches arcuate step 30. Blade retaining means 32 includes a stepped blade seating member 36 integrally formed with and extending from cover 15, notches 37 and 38 formed in cup shaped member 14, and L-shaped seating member 39 integrally formed with and extending from cup shaped member 14. Blade retaining means 32' includes an L- shaped seat member 40 and substantially rectangular shaped retaining member 41 both of which are integrally formed with and extending from cover 15, and L-shaped seat 42 and notches 43, 44 and 45 formed in cup shaped member 14.

When the various components of the retaining means are placed in their proper relationship by placing cover 15 over the opening of cup shaped member 14, and when contact blades are inserted in slots formed by the inter-relationship of the parts, the contact blades will be cantilevered at one end with their other ends being free to bend in accordance with the actuation induced by cam programming means 29. When the arcuate step 30 of the cam programming means again reaches the cam follower 33, blade 18 will return to the position shown, with blade 19 being stopped at the step 36' of stepped support member 36, thus breaking the electrical contact between contacts 34 and 35. Contact blades 18 and 19 preferably include elongated apertures 18" and 19" which extend beyond the bend of the blades so that the blades can be more easily deflected for a given thickness of blade.

As is more clearly discussed in US. Pat. No. 3,500,005 Variable Circuit Timer issued Mar. 10, 1970 to W. R. Brown, various switching sequences can be provided by providing various cams with various steps and by using a proper number of contact blades properly carried by the retaining means and the seating means.

Shaft 13 can be either motor driven or can be manually rotated through knob 33 so that a desired setting, such as the program starting point, may be manually set. In order that the manual rotation may be independent of the motor drive means, a clutch means 50 is provided. Referring to FIG. 1 and 2 clutch means 50 includes a coil spring 52 frictionally carried on a hub 7 of gear 7 and having a distal end 54 coupled to the shaft 13. As shown the distal end is coupled to the shaft 13 through a loose fitting engagement with slot 56 provided inhub 58 of cam 29' and through further engagement with aperture 60 provided in shaft 13. Spring 52 is preferably square or rectangular in cross-section for better frictional engagement with the hub 7'. When shaft 13 is being driven through the motor drive means; the coil 52 will tighten about the hub 7' due to its frictional engagement therewith, thus causing the coil to rotate with the gear 7. The shaft 13 will then be driven through the coupling of the distal end 54 of the spring with the shaft. During manual rotation of the shaft in the proper direction, the frictional engagement of the coil with the hub 7 of the gear will not be sufficient to overcome the counter force of the gear train of the motor drive means, thus allowing the coil to slip on the hub. Manual rotation is thus effected, independent of the motor drive means.

The present arrangement of the clutch means provides several advantages particularly with regard to its use in the described timing mechanism. The spring is coiled about and slips on one member only; thus contributing to compactness and neatness. The distal end 54 serves as a drive means for the shaft as well as a retainer for trapping the shaft against axial movement through the engagement of the distal end of the slot 56 and the aperture 60. This eliminates using other trapping means such as staking the shaft to another part or using a retaining ring. And by changing directional rotation of the motor and the winding direction of the spring clockwise or counterclockwise rotation becomes readily optional.

Thus there is described a timer which is neat and compact and which has a clutch means which is simple yet serves purposes other than clutching as well.

What is claimed is:

1. In a timer having electrical switch means responsive to rotation of a cam programming means, said cam programming means responsive to manual drive means and motor drive means: a clutch means permitting said cam programming means to be manually rotated independent of said motor comprising a coil spring frictionally carried by a member of said motor drive means, said coil spring including a distal end extending from a coil of said coil spring and engaging said cam programming means.

2. In a timer according to claim 1 wherein said distal end engages a cam of said cam programing means.

3. In a timer according to claim 1 wherein said cam programming means includes a shaft and said distal end engages said shaft.

4. In a timer according to claim 1 wherein said cam programming means includes a shaft and said distal end engages said shaft and a cam carried by said shaft.

5. In a timer according to claim 1 wherein said cam programming means includes a shaft and said member includes a gear carried by said shaft and said spring is frictionally carried by a hub of said gear.

6. In a timer according to claim 1 wherein said cam programming means includes a shaft and said member includes a gear carried by said shaft, and said spring is frictionally carried by a hub of said gear, said distal end engaging a slot in a hub of a cam of said cam programming means and an aperture in said shaft.

7. In a timer according to claim 1 wherein at least a portion of said coil spring carried by said member is flat.

8. In a timer according to claim 1 wherein said coil of said coil spring is square in cross-section.

9. In a timer according to claim 1 wherein said coil of said coil spring is rectangular in cross-section.

10. A timer comprising:

a. a housing including a cup-shaped member and a cover adapted to close the same,

b. a cam programming means including a shaft means carrying at least one cam,

c. retaining means integrally found with said housing,

d. at least two contact blades carried by said retaining means so as to cantilever said contact blades, electrical contacts carried by said contact blades and adapted to engage one another,

e. cam follower means carried by one of said contact blades responsive to said cam programming means,

f. stop means disposed at the free ends of said blades,

g. motor drive means including gear train means applying power driven rotation to said shaft,

h. means coupled to said shaft for manual rotation thereof, and

i. clutch means comprising: a gear of said gear train means independently rotatably carried by said shaft, a coil spring frictionally carried by said gear and having a distal end extending from a coil of said coil spring, the distal end of said spring coupled to said shaft.

11. A timer according to claim 10 wherein said contact blades include elongated centrally disposed apertures.

12. A timer according to claim 10 wherein said contact blades are L-shaped, and include elongated centrally disposed apertures extending past said bend.

13. A timer according to claim 10 wherein said distal end of said spring engages a slot in a cam of said cam programming means.

14. A timer according to claim 10 wherein saod distal end of said spring engages an aperture in said shaft.

15. A timer according to claim wherein said distal end of said spring engages a slot in a cam of said cam programming means and a aperture in said shaft.

16. In a timer according to claim 10 wherein at least a portion of said coil spring carried by said member is flat.

17. In a timer according to claim 10 wherein said coil of said coil spring is square in cross-section.

18. In a timer according to claim 10 wherein said coil of said coil spring is rectangular in cross-section.

19. A timer comprising:

a. a housing including a cup-shaped member and a cover adapted to close the same,

b. a cam programming means including a shaft means carrying at least one cam,

c. retaining means integrally formed with said housd. at least two contact blades carried by said retaini. clutch means comprising: a gear of said gear train means independently rotatably carried by said shaft, a coil spring frictionally carried by said gear and having a distal end, the distal end of said spring coupled to said shaft, and

j. said blade retaining means comprising: an L- shaped seat formed in said cup shaped member, an L-shaped seat and a rectangular shaped member extending from said cover, and notches formed in said cup shaped member adapted to receive said L-shaped seat and said rectangular shaped member extending from said cover, insertion of said seat and said rectangular shaped member extending from said cover, insertion of said seat and said rectangular shaped member in said notches providing slots receiving said contact blades to cantilever the same; and wherein said stop means comprises a stepped seating member extending from said cover, and notches and an L-shaped seat member formed on said cup shaped member, insertion of said stepped seating member into said notches providing a slot between said stepped seating member and said L-shaped seat member, said stepped seating member disposed to receive and stop at least one free end of said contact blades, and said slot adapted to receive an additional contact blade. 

1. In a timer having electrical switch means responsive to rotation of a cam programming means, said cam programming means responsive to manual drive means and motor drive means: a clutch means permitting said cam programming means to be manually rotated independent of said motor comprising a coil spring frictionally carried by a member of said motor drive means, said coil spring including a distal end extending from a coil of said coil spring and engaging said cam programming means.
 2. In a timer according to claim 1 wherein said distal end engages a cam of said cam programing means.
 3. In a timer according to claim 1 wherein said cam programming means includes a shaft and said distal end engages said shaft.
 4. In a timer according to claim 1 wherein said cam programming means includes a shaft and said distal end engages said shaft and a cam carried by said shaft.
 5. In a timer according to claim 1 wherein said cam programming means includes a shaft and said member includes a gear carried by said shaft and said spring is frictionally carried by a hub of said gear.
 6. In a timer according to claim 1 wherein said cam programming means includes a shaft and said member includes a gear carried by said shaft, and said spring is frictionally carried by a hub of said gear, said distal end engaging a slot in a hub of a cam of said cam programming means and an aperture in said Shaft.
 7. In a timer according to claim 1 wherein at least a portion of said coil spring carried by said member is flat.
 8. In a timer according to claim 1 wherein said coil of said coil spring is square in cross-section.
 9. In a timer according to claim 1 wherein said coil of said coil spring is rectangular in cross-section.
 10. A timer comprising: a. a housing including a cup-shaped member and a cover adapted to close the same, b. a cam programming means including a shaft means carrying at least one cam, c. retaining means integrally found with said housing, d. at least two contact blades carried by said retaining means so as to cantilever said contact blades, electrical contacts carried by said contact blades and adapted to engage one another, e. cam follower means carried by one of said contact blades responsive to said cam programming means, f. stop means disposed at the free ends of said blades, g. motor drive means including gear train means applying power driven rotation to said shaft, h. means coupled to said shaft for manual rotation thereof, and i. clutch means comprising: a gear of said gear train means independently rotatably carried by said shaft, a coil spring frictionally carried by said gear and having a distal end extending from a coil of said coil spring, the distal end of said spring coupled to said shaft.
 11. A timer according to claim 10 wherein said contact blades include elongated centrally disposed apertures.
 12. A timer according to claim 10 wherein said contact blades are L-shaped, and include elongated centrally disposed apertures extending past said bend.
 13. A timer according to claim 10 wherein said distal end of said spring engages a slot in a cam of said cam programming means.
 14. A timer according to claim 10 wherein saod distal end of said spring engages an aperture in said shaft.
 15. A timer according to claim 10 wherein said distal end of said spring engages a slot in a cam of said cam programming means and a aperture in said shaft.
 16. In a timer according to claim 10 wherein at least a portion of said coil spring carried by said member is flat.
 17. In a timer according to claim 10 wherein said coil of said coil spring is square in cross-section.
 18. In a timer according to claim 10 wherein said coil of said coil spring is rectangular in cross-section.
 19. A timer comprising: a. a housing including a cup-shaped member and a cover adapted to close the same, b. a cam programming means including a shaft means carrying at least one cam, c. retaining means integrally formed with said housing, d. at least two contact blades carried by said retaining means so as to cantilever said contact blades, electrical contacts carried by said contact blades and adapted to engage one another, e. cam follower means carried by one of said contact blades responsive to said cam programming means, f. stop means disposed at the free ends of said blades, g. motor drive means including gear train means applying power driven rotation to said shaft, h. means coupled to said shaft for manual rotation thereof, and i. clutch means comprising: a gear of said gear train means independently rotatably carried by said shaft, a coil spring frictionally carried by said gear and having a distal end, the distal end of said spring coupled to said shaft, and j. said blade retaining means comprising: an L-shaped seat formed in said cup shaped member, an L-shaped seat and a rectangular shaped member extending from said cover, and notches formed in said cup shaped member adapted to receive said L-shaped seat and said rectangular shaped member extending from said cover, insertion of said seat and said rectangular shaped member extending from said cover, insertion of said seat and said rectangular shaped member in said notches providing slots receiving said contact blades to cantilever the same; and wherein said stop means comprises a stepped sEating member extending from said cover, and notches and an L-shaped seat member formed on said cup shaped member, insertion of said stepped seating member into said notches providing a slot between said stepped seating member and said L-shaped seat member, said stepped seating member disposed to receive and stop at least one free end of said contact blades, and said slot adapted to receive an additional contact blade. 